@SuppressWarnings("nullness")
    ListenableFuture<List<V>> nonNull = nullable;
    return nonNull;
  }

  /**
   * Creates a {@link FutureCombiner} that processes the completed futures whether or not they're
   * successful.
   *
   * <p>Any failures from the input futures will not be propagated to the returned future.
   *
   * @since 20.0
   */
  @SafeVarargs

        // Should not throw any exception during normal execution
        curtainFinallyHook.hook(assistantDirector);

        // Verify that the method completes without errors
        assertTrue(true); // Method completed successfully
    }

    // Test hook method when MultiThreadedHttpConnectionManager class is not available
    public void test_hook_classNotFound() {
        // Create a custom hook that simulates class not found scenario

    taskRunner.withLock {
      check(currentTask == TestThreadSerialTask)
      nanoTime = newTime
      yieldUntil(ResumePriority.AfterOtherTasks)
    }
  }

  /** Confirm all tasks have completed. Used by the test thread only. */
  fun assertNoMoreTasks() {
    taskRunner.assertLockNotHeld()

    taskRunner.withLock {
      assertThat(activeThreads).isEqualTo(0)
    }
  }

 * it is invoked using this executor once the future's computation is {@linkplain Future#isDone()
 * complete}. If the computation has already completed when the listener is added, the listener will
 * execute immediately.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/ListenableFutureExplained">{@code
 * ListenableFuture}</a>.

                    }
                });
            }

            startLatch.countDown(); // Start all threads
            boolean completed = endLatch.await(10, TimeUnit.SECONDS);
            executor.shutdown();

            assertTrue(completed, "All threads should complete without deadlock");
            assertEquals(threadCount * operationsPerThread, completedOps.get(), "All operations should complete");

     */
    /**
     * Human-readable error messages corresponding to DOS error codes.
     * Array of descriptive strings for each DOS error condition.
     */
    String[] DOS_ERROR_MESSAGES = { "The operation completed successfully.", "Incorrect function.", "Incorrect function.",
            "The system cannot find the file specified.", "Bad password.", "The system cannot find the path specified.", "reserved",

     */
    /**
     * Human-readable error messages corresponding to DOS error codes.
     * Array of descriptive strings for each DOS error condition.
     */
    String[] DOS_ERROR_MESSAGES = { "The operation completed successfully.", "Incorrect function.", "Incorrect function.",
            "The system cannot find the file specified.", "Bad password.", "The system cannot find the path specified.", "reserved",

    return insertAt == 0
  }

  /**
   * Schedules immediate execution of [Task.tryCancel] on all currently-enqueued tasks. These calls
   * will not be made until any currently-executing task has completed. Tasks that return true will
   * be removed from the execution schedule.
   */
  fun cancelAll() {
    taskRunner.assertLockNotHeld()

    taskRunner.withLock {
      if (cancelAllAndDecide()) {

          }
        };

    recursiveCache = CacheBuilder.newBuilder().weakKeys().weakValues().build(recursiveLoader);
    cacheRef.set(recursiveCache);

    // tells the test when the computation has completed
    CountDownLatch doneSignal = new CountDownLatch(1);

    Thread thread =
        new Thread() {
          @Override
          public void run() {
            try {

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event { #shutdown-event }

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

{* ../../docs_src/events/tutorial002.py hl[6] *}